Hydraulically controlled machine tool



Aug. 27, 1946. w. R. TUCKER HYDRAULICALLY CONTROLLED MACHINE TOOL I 2 Sheets-Sheet l Filed April 27, 1942 INVENTOR BY Jaw AfiW I ATTORNEYS- Aug. 27, 1946. w. R. TUCKER HYDRAULICALLY CONTROLLED MACHINE TOOL- 2 Shets-Sheet 2 Filed April 27, 1942 INVENTOR I ATTORNEYS Patented Aug. 27, 1946 HYDRAULICALLY CONTROLLED MACHINE TOOL Warren R. Tucker, Dayton, Ohio, assignor to The Hydraulic Development Corporation, Inc., Wilmington, Del., a corporation of Delaware Application April 27, 1942, Serial No. 440,733

6 Claims.

This invention relates to hydraulic machinery and, in particular, to hydraulically controlled machine tools.

It is an object of this invention to provide a hydraulically powered and controlled device adapted to perform a combined rotary and reciprocating motion, such as drilling, reaming and honing.

It is another object to provide a device including a reciprocable member which may be hydraulically controlled so as selectively to be reciprocated, for instance for broaching or pressing purposes, or so as simultaneously to be reciprocated and rotated for operations, such as drilling, reaming and honing.

It is another object of the invention to provide a device which comprises a member adapted simultaneously to be reciprocated and rotated hydraulically, and in. which the reciprocable member will automatically be retracted temporarily in response to a predetermined resistance encountered by said member, and will again be advanced when said resistance has decreased.

A still further object of the invention consists in the provision of a hydraulic system comprising a plurality of members adapted. simultaneously to be reciprocated and rotated, in which the reciprocative and rotative movement of said members may be controlled by a single pressure fluid source.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which: H

Figure 1 diagrammatically illustrates a machine tool accordingto the invention.

Figure 2 shows, on a larger scale, a partial section of the device illustrated in Figure 1.

. Figure 3 is a section along the line 3-3 of Figure 2.

Figure 4 is a section along the line 4-4 of Figure 3.

Figure 5 shows a system including a plurality of machine tools according to the invention.

General arrangement The device according to the present invention consists of a fluid operable plunger rotatably supporting a tool holder, and a hydraulically operable rotary motor for rotating said tool holder.

Furthermore, control means are provided which are adapted to control the supply of pressure fluid to the fluid operable plunger and the rotary motor so as selectively to cause reciprocation and simultaneously rotation of the tool holder, or to reciprocate said tool holder without rotating the same.

When the tool holder is to be advanced while it is rotating, as is the case when drilling, hydraulically operable control means may, according to another feature of the'invention, be provided, which will cause a temporary retraction of the tool holder if the rotation of the tool is accidentally stopped, for instance, when the tool encounters undue resistance in the material to be machined.

Structural arrangement 7 Referring now to the drawings in detail, the device shown therein comprises a casing, generally designated Ill, having connected thereto, in any convenient manner, two cylinders II and I2, in which are reciprocably mounted two ciprocable in the cylinder bore 20 and connected to a piston shaft 2|. The piston l9 and piston shaft 2| are hollow and have mounted therein anti-friction bearings 22, 23 and 24 which, in their turn, support a tool holder 25. The tool holder 251s rotatable within the piston l9 and piston shaft 2| and has rigidly connected thereto a rotor 26 of a rotary motor 21, which may be of anydesired type, preferably of the type shown in Figure 4. According to Figure 4, the rotor 26 is provided with a plurality of radial slots 28 having reciprocably mounted therein vanes 29 which engage the inner periphery 30 of the motor casing 3|.

The motor casing 3| is provided with two opposed flat .suriaces 32 slidable. on correspondingly shaped surfaces 33 in piston IS. The motor casing 3| is continuously urged toward the right with regard to Figure 4 by means of a spring 35, one end of which rests in a recess 36 provided in the piston |9, while the other end of the spring 35 engages the motor casing 3|. I a

An eccentric 31 is provided which is connected to a control rod 38 (Figure 3), which latter is rotatable by means of a worm wheel 39 and worm 40. By rotating the eccentric 31 from the position shown, the motor casing 3| will beshifted toward the left with regard to Figure 4 agains the thrust of the spring 35. e

'The inner space of the motor casing 3| is adapted to communicate with a passageway 4| through'a bore 42in the motor casing 3|. A

b ore 43 is adapted to connect'a portion of the interior ,of the motorcasing 3| with a passage Way 44. "The passageway 44 leads through the plunger and communicates with a conduit 45 which, in itsturn, communicates with onejend of the cylinder II and also communicates witha valve 46. The valve46 comprises a valve casing 41 and a; rotor 48, rotatable in the casing 41 and isprovided with a recess. adapted inone posiconduits51 and 99, while establishing fluid connection between the latter and the conduit 91.-

hand area of the piston I9 so as to initiate a retraction'stroke of the piston I9 and piston shaft 2I and, consequently, also of the tool holder 25 supported thereby. It will be noted that the total effective area on the right hand of the piston I9 is larger than the combined area of the pistons I 5 and I1, while the left hand area ofthe piston I9 still remains connected to the tank 19. This immediately reduces the resistance encountered by the drill 89. As a result thereof, the pressure prevailingin the passageway and bore 43 is again able to rotate the rotor 26 and, thereby, the tool holder25 so that the drill 89 again rotates. Therefore, the pressure in the conduit 45 again drops, which also results in a reduction of the pressure in the pilot line '14. Consequently,v the spring 66 again moves the plunger 64 and the valve member 59 into their initial position shown in Figure. 1. This re-establishes the previous condition, in which the conduits 69 and 51 communicate with each other, while fluid connection is prevented between the conduits 69 and 61. The conduit 69, therefore, is again connected to the tank 19, and the pressure acting on the pistons I5 and I1 moves the piston shaft 2| and, thereby, the tool holder 25 to the right. In this way, the advancing movement of the drill is continued for completion of the working operation.

When the working operation has been completed, the operator shifts the valve rotor 82 in anti-clockwise direction so that themark 92 will be in alignment with the mark 95. In this position, the conduits 59 and 51 Will be connected through the recesses'89 and 81 and the bores 98 with the pressure line 69, while the conduit 53 communicates through the passageway 83, bore 85 and port 8| with the conduit 89 leading to the tank 19. Consequently, pressure fluid from the pump 19 passes through the recess 86, conduits 59 and 45 into the left end of the cylinders II and I2.

A part of the pressure fluid in conduit 45 passes through the passageway 44 and into the motor casing 3| where it acts upon the vane 29 so as to rotate the rotor 26. In other words, the drill 89 continues its rotation. Simultaneously, pressure fluid from the pump 19 flow through the conduit 69, recess 81, conduit 51, three-way valve 58 and conduit 69 into the right hand end of the cylinder bore 29 where it acts upon the right hand side or retraction side of the piston I9.

I Inasmuch as the eflective'retraction area of x the piston I9 is larger than the total area of the pistons I5 and I1, as mentioned above, the piston shaft 2| moves toward the left, while the tool holder 25 still rotates. In this way, the drill 89 is retracted from the work piece which has just been machined.

When the piston I9 has reached the end of its retraction stroke, and it is desired to stop rotation of the drill, the operator shifts the valve rotor 48 in clockwise direction so that the mark 99 will be in alignment with the mark 96. This interconnects the conduits 45'and 53, While preventing fluid communication between the said two conduits and the conduit 59. Consequently, the pressure in the conduit 69 soon increases to such an extent that, while being conveyed through the conduits 51, 69 and the. pilot line 12, it actuates the. servomotor 13 so as to-shii't the pump 19 to neutral or no delivery position.

If it is now dsired to reciprocate the tool holder 25, for. instance for broaching or for pressing purposes, the operator replaces the drill 89 by a corresponding broaching device. or by .a desired pressing plunger. Thereupon the operator closes the shutoff valve 58 and shifts the valve rotor 82 in clockwise direction so that themark 92 .will be in aligmnent with the mark 91. It will be noted that, during this shifting movement, the. valve rotor 82 passesits previous position for has no effect whatsoever on the tool holder 25.

When the valve rotor 82 occupies the position in which the marks 92 and 91 register with each other,'pressure fluid from the line 69 is conveyed through the recesses 81 and 86, which are interconnected through the passageway. 98in'to the conduit 53; From here the pressure fluid passes through the conduit 55'to the left hand or advancing area of the piston I9. Simultaneously, fluid passes from the conduit 53 through the recess 49 and the conduit 45 to cylinders II and I2. I

Since, on the other hand, the conduit 69" is connected through the three-way'valve 58, the

the passageway 4I, so that the pressure on both sides of the motor 21 is balanced and no rotation of the rotor 26 is effected. When the piston. I9 has reached the end of its advancing stroke, the pressure in conduit 69 in-' creases and, being conveyed through the pilot line 12, actuates the servomotor 13 so as to move the pump 19 to neutral or no delivery position. Con:

sequently, the tool holder 25 comes to a halt.

To effect a retraction stroke of the tool holder 25, the operator rotates the valve rotor 82 in anti-clockwise direction until the mark 92 regis-. ters with the mark 95. Fluid pressure from the pump 19 then passes through the conduit 69, recess 81, conduit 51, three-way valve 58, conduit and check valve 6| into the right hand end of the cylinder bore 29, where it acts upon the retraction side of the piston I9. valve rotor 82, the conduits 53, 55 and 45 are connected through the passageway 83, bore 85, port- 8I and conduit 99 with the fluidtank 19. There fore, the pressure now acting on the retraction side of the piston I9 moves the latter and, there by, the tool holder 25 toward the left so as to re'- In case the device shown in Figure 1 isto be;

the left end of the In this position of the.

, through the conduit 45 and passageway 44 to'the motor 21 will then be used merely for rotating the tool holder 25 which, in this instance'carries a milling tool. r

From the above it will be clear that the device ofFigure 1 is of great universal use, inasmuch as the tool holder '25 may selectivelyv be advanced and simultaneously rotated, or ,may be rotated without being advanced, or may be advanced without'being rotated. a i It should also be noted that the adjustment of the chok valve 63 will control the rate of advancement of the tool holder 25, while the speed of rotation of the tool holder 25 may be varied in accordance with the adjustment of the eccen trio 3! and the eccentricity of the inner periphery 30 of the motor casing 3 I relative to the periphery of the rotor 26. 3 7

It will furthermore be noted that b adjusting thechoke 15 the initiation of the advancement of the tool holder 25, following a temporary retraction of the latter, can be more or less delayed, thereby assuring that, when the tool holder is again advanced, a proper advancing pressure is acting upon the latter. r l I Referring now to th rarrangement of Figure 5, the operation thereof is similar to that described above in connection with Figure 1, By movement of the'valve rotor of the ,valve 46a and shifting the valve rotor of the valve 52a into the positions referred to in connection with the description of the device shown in-Figure 1, the

tool holders 25a, 25b and 250 may selectively be advanced and simultaneously rotated, or may be reciprocated'without being rotated. By looking the tool holders 25a, 25b and 250, by means .of the locking screws Sta, 99b and 9&0, and a correspond ing position of the valves 46a and 52a, the tool holders 25a, 25b and 250 may be rotated without being reciprocated. I

It will be noted that a single pump, namely the pump 10a, supplies fluid for actuating the several tool holders 25a, 25b and 250, while the fluid mo tor in'e'ach of the casings Ilia, lb and lilc may be adjusted for any desired ratio of rotary speed, the actual speeds being a function of the quantity of fluid supplied through the valves 88. This con-' stitutes a material advance and saving over similar devices heretofore known, in which it was 7 2. In combination, a reciprocablemember, fluid operable advancing and retracting means associated with said member for reciprocating o the same, fluid operable motor means operable to rotate said member while it isbeing reciprocated, a single valve controlling the supply of fluid to said motor means for selectively causing; said reciprocable member to reciprocate While simultaneously rotating, or to reciprocate without rotating, and means responsive to a predetermined resistance exerted on said member for' tem'e.

lective'ly for rotating said member while it is being reciprocated, control 'means for controlling the supply of pressure fluid selectively to saidadvancing or said retracting meam, pressure 1'62 sponsive means responsive to a predetermined pressure at theinlet side of said motor means while said member is being advanced for causing a temporary retraction of said reciproc'able member, and means associated with said pressure responsive means and operable subsequently to V the actuationof the latter in response to a detor.

6. In combinatioma machine tool spindle, first hend within my invention such modifications as I come within the scope of the claims. Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In combination, a reciprocable member, fluid operable advancing and retracting means associated with said member for reciprocating the same, fluid operable motor means operable selectively for rotating said member while it is being reciprocated, and means adapted in responseto a predetermined resistance exerted upon said re'ciprocable member, during the ad vancing stroke thereof, for temporarily retract ing said member, and also adapted in response to adecrease in the said resistance to again advance said member. 7

crease in the pressure at'the inlet side of said motor means below said predetermined pressure for again advancing said reciprocable member.

4. In combination, a reciprocable member, fluid operable advancing and retracting means associated with said member for reciprocating the same, fluid operable rotary motor means associ:-

ated with said reciprocable member and oper- V able selectively to rotate the latter while his being reciprocated, means operable selectively for varying therspeed of rotation of said recipro cable member, means adapted in response to a predetermined resistance exertedlupon saidreciprocable member, durin the advancing stroke thereof, for retracting said member and also adapted, in response to ,a decrease in said resistance, to again advance said member and means controlling the rate of advanoefrom' said retracted position.

5. In combination, a reciprocable member, fluid op-erabie advancing and retracting means associatedwith said member for reciprocating the same, fluid operable rotary motor 'rneans associ-' atedwith said reciprocable member and operable selectively to rotate the latter'while it is being reciprocated, channel means in said reciprocat ing member for supplying pressure fluid to said rotary motor, and a single'valve operable-to control said reciprocab'le member and said fluid moturning said spindle'to work engaging position 7 after a predetermined time period, and a single valve for controlling the supply of fluid to said motors for actuating said motors simultaneously or said first motor independently,

WARREN R. TUCKER, 

